Bidding on Users

ABSTRACT

In one implementation, a computer-implemented method includes receiving at a server a request from an advertiser to target an ad to users of a computer-implemented social network, the request comprising data representing characteristics of the users that the advertiser desires to target. The method further includes ranking the users based on how similar the users&#39; characteristics are to the received characteristics and an influence score for each user that indicates how influential the user is within the social network. The method also includes scoring the advertiser&#39;s request based on a bid from the advertiser for an opportunity to display the ad to one or more of the users and assigning the opportunity to display the ad to the one or more users based on a correlation between a score of the advertiser&#39;s request and one or more rankings of the one or more users.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 61/157,075 to Zhang et al., entitled “Bidding on Users” andfiled Mar. 3, 2009, the contents of which are incorporated herein byreference.

TECHNICAL FIELD

This document generally describes methods and systems for placingadvertisements on a social network.

BACKGROUND

The present disclosure generally relates to providing advertising tousers of a social network. A social network may be an online system thatprovides a forum for users geographically separated to interact with oneanother. Social networks can be aimed at different aspects of socialinteraction, such as friendship and business networking.

Methods of advertising to users of a social network have includedtargeting the social network and users of the social network withspecific content. In some methods, the entire social network has beentargeted with advertisements directed to the general purpose of thesocial network (e.g., business). In other methods, specific users havebeen targeted with advertisements based upon the content of each user'sprofile page. For example, were a user to discuss sports on his/herprofile page, an advertisement regarding sports may be targeted at theuser.

SUMMARY

This document describes techniques for providing advertising to users ofa social network. In general, a viewer's interactions with particularadvertisements may be monitored, such as the advertisements the userskips, and the system may then select other advertisements that aredetermined to be more like advertisements the user has watched and lesslike those the user has skipped.

In one implementation, a computer-implemented method includes receivingat a server a request from an advertiser to target an ad to users of acomputer-implemented social network, the request comprising datarepresenting characteristics of the users that the advertiser desires totarget. The method further includes ranking by the server the usersbased on how similar the users' characteristics are to the receivedcharacteristics and an influence score for each user that indicates howinfluential the user is within the computer-implemented social network.The method also includes scoring by the server the advertiser's requestbased on a bid from the advertiser for an opportunity to display the adto one or more of the users targeted by the advertiser and assigning bythe server the opportunity to display the ad to the one or more userstargeted by the advertiser based on a correlation between a score of theadvertiser's request and one or more rankings of the one or more users.The method further includes outputting by the server the ad for displayon one or more clients associated with the one or more users assigned tothe ad.

In another implementation, a system for assigning an opportunity todisplay an ad to users of a social network includes one or more serversand an interface to one or more of the servers to receive from anadvertiser a request to target an ad to users of a social network, therequest comprising data representing characteristics of the users thatthe advertiser desires to target. The system further includes means forranking the users based on how similar the users' characteristics are tothe received characteristics and an influence score for each user thatindicates how influential the user is within the social network and arequest scoring module installed on the one or more servers to score theadvertiser's request based on a bid from the advertiser for anopportunity to display the ad to one or more of the users targeted bythe advertiser. The system also includes an ad assignment moduleinstalled on one or more of the servers to: assign the opportunity todisplay the ad to the one or more users targeted by the advertiser basedon a correlation between a score of the advertiser's request and one ormore rankings of the one or more users, and output the ad for display onone or more clients associated with the one or more users assigned tothe ad.

In another implementation, a computer-implemented method includesreceiving at a server information related to a content of an ad from anadvertiser and creating by the server an ordered list of users of acomputer-implemented social network based on a likelihood a user will bereceptive to the content of the ad and an amount of influence a user hasover other users of the computer-implemented social network. The methodfurther includes receiving at the server a bid from the advertiser for aright to display the ad to a user provided in the ordered list of usersand awarding by the server the right to display the ad to the user tothe advertiser if the bid from the advertiser is greater than other bidsreceived within a time period from other advertisers for the right todisplay the ad to the user, wherein the bid from the advertiser isreceived within the time period. The method also includes outputting bythe server the ad for display on a client associated with the user.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features, objects, andadvantages of the invention will be apparent from the description anddrawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram of an example system for receiving bids foropportunities to advertise to users of a social network and forpropagating ads from user to user across a social network.

FIG. 2 is another diagram of an example system for receiving bids foropportunities to advertise to users of a social network and forpropagating ads from user to user across a social network.

FIG. 3 is a flow chart of example process for awarding an opportunity todisplay an ad to users of a social network based upon advertiserrequests.

FIG. 4 is a flow chart of example process, respectively, for recursivelypropagating an ad across users of a social network.

FIG. 5 is a flow chart of example process, respectively, for generatinga model of a user's interests from user generated content.

FIG. 6 is a flow chart of example process, respectively, for anadvertiser to place bids for opportunities to display ads to users of asocial network.

FIG. 7 is a flow chart of example process, respectively, for propagatingan ad from a propagating user to a recipient user.

FIG. 8 is a schematic diagram of a computer system.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

This document generally describes a placement of advertisements on asocial network. More specifically, the document describes an allocationof opportunities to display ads to users and a propagation of ads acrossthe social network. In some instances, a method and system is describedby which an advertiser can target ads to users of a social networkaccording to a user's interests and influence on the social network. Anopportunity to display an ad to an influential user with interestsrelevant to the ad may be more valuable to an advertiser than anopportunity to display an ad to a non-influential user with unrelatedinterests (or even a non-influential user with related interests). Auser's influence on a social network may be determined by looking at theuser's level of activity and/or acquaintance relationships on the socialnetwork. An advertiser may receive a ranked list of anonymous usersaccording to user interest and influence. A bidding mechanism may beused to accommodate multiple advertisers seeking to obtain theopportunity to display ads to a finite number of relevant, influentialusers on a social network.

In some instances, once an opportunity to display an ad to a specificanonymous user has been awarded to an advertiser, an ad from theadvertiser may be propagated from the user to the user's friends using aheat diffusion model. For instance, a user's influence on the socialnetwork can be represented as a heat intensity or a heat score, whereusers with more influence have a higher heat score. Propagation betweenusers can then be modeled using a heat diffusion model. For example, anad may spread (propagate) between two connected users as long as theuser targeted with the ad has greater “heat” than the user yet to betargeted. This may result in ads propagating throughout the socialnetwork from more influential users to less influential users. Oneadvantage that may be gained from the described method is the ability ofadvertisers to maximize advertising efficiency by propagating ads frominfluential users to influenced users.

FIG. 1 is a diagram of an example system 100 for receiving bids foropportunities to advertise to users of a social network and forpropagating ads from user to user across a social network. The system100 can include advertisers 102 a-102 c, a server that receives bids112, and a social network 118.

An advertiser 102 a may submit a request to display an ad 108 to usersof a social network having certain characteristics 106. The server 112may receive the request and provide the advertiser 102 a with a list ofanonymized users ranked according to user influence score and/or usersimilarity to the requested characteristics 114. The advertiser 102 amay then provide a bid for an opportunity to display the ad 108 to oneor more of the ranked users 114. The server 112 may receive bids 104 band 104 c from multiple advertisers 102 b and 102 c for the opportunityto display an ad to a certain anonymous user 114. For example, in bidchart 114 there are two bids ($1.50 for a sports ad and $0.60 for amusic ad) for the opportunity to display an ad with user U4. The server112 may then award the opportunity to display an ad to the highestbidder, at which point the ad 116 may be displayed on the social network118.

The ad first may be displayed to the user that was anonymously bid upon(e.g., user U4 120). An ad 116 may then be propagated throughout thesocial network 118 along the connections between users. For instance,the ad may propagate from one user connected to another as long as theheat, or influence, score for the propagating user is greater than theheat score for the recipient user. For example, user U4 120 is connectedto user U17 122. User U4 has a heat score of 500 and user U17 has a heatscore of 450 114. An ad may propagate from user U4 120 to user U17 122because the heat score of U4 is greater than U17. However, the ad maynot propagate from user U4 120 to user U2 126 because the heat score ofU2 is 510 and is greater than the heat score of user U4 114.

FIG. 2 is another diagram of an example system 200 for receiving bidsfor opportunities to advertise to users of a social network and forpropagating ads from user to user across a social network. The system200 may include a client side 202 and a server side 204. The client side202 may interface with advertisers 206 to submit requests and bids todisplay advertisements to selected users of a social network.Additionally, the client side 202 can interface with users 208 todisplay the advertisements submitted by the advertisers 206 within, forexample, pages viewed by the users on the social network. The serverside 204 can receive advertiser 206 requests and award opportunities todisplay advertisements to selected users 208 through a bidding process.The server side 204 can also propagate advertisements, for example,using a heat diffusion model among users 208 of a social networkconnected by an acquaintance relationship (e.g., the users aredesignated as friends, the users visit each others' profiles, etc.).

The client side 202 can include an advertiser 206 that submitscharacteristics of users to which the advertiser 206 wishes to targetads. An advertising interface referred to here as the Adheat interface210 can receive the characteristics and pass them to the server side204. The server side 204 can include a webserver 214 that receives thecharacteristics and, through the use of a database 216, produces a listof users ranked by each user's influence on the social network andsimilarity to the characteristics submitted by the advertiser. Afterranking, the webserver 214 can then pass the ranked list to the clientside 202 in some implementations.

In some implementations, the webserver 214 may create an ordered list ofusers in response to receiving an ad and/or content of an ad from theadvertiser 206. The ordered list may order the users according alikelihood a user will be receptive to the content of an ad and/or anamount of influence a user has over other users of a social network.Users listed near the top of the ordered list may be more likely to bereceptive to the content of an ad and/or more influential over otherusers of a social network than users listed near the bottom of theordered list.

The Adheat interface 210 at the client side can receive and provide theranked list of users to the advertiser 206. The advertiser 206 canprovide the Adheat interface 210 with bids for opportunities to displayan ad to selected users on the ranked list. The Adheat interface 210, inturn, can pass the bids to the server side 204. After receiving thebids, the webserver 214 can run an auction and award opportunities todisplay ads to ranked users based upon the bids. The auction process issubsequently described in more detail.

The webserver 214 can transmit ads to the client side 202. A gadget 212on the client side 202 can display to the users 208 ads provided by theadvertisers 206 that won an opportunity to be displayed to the users208. The ad can then be propagated through the social network,represented here using a friendship graph 218. This is described in moredetail below.

As mentioned advertiser 206 may provide the Adheat module 210 with arequest to target users of a social network with an ad. The request mayinclude information specifying the ad's content and/or characteristicsof the users the advertiser 206 desires to target with the ad.Characteristics of a user may include demographic information such as anage or age range, a gender, interests, an occupation, income, education,or geographic location of a user.

In some instances, the advertiser 206 may provide the Adheat module 210with one or more keywords related to users whom the advertiser wishes totarget. For example, the advertiser 206 may provide the Adheat module210 with a request to display an ad related to “sports” to “male” users“between the ages of 18 and 35.”

In some implementations, the advertiser 206 may select descriptors forthe content of the ad and the characteristics of the users theadvertiser 206 desires to target with the ad from a drop-down menu. Forexample, drop down boxes may offer advertisers a number of usercharacteristics from which to select. In some instances, the advertisermay provide the ad itself to the Adheat module 210 and the Adheat module210 may analyze the ad and determine the content of the ad. An adprovided to the Adheat module 210 may be text, an image, a video, or anycombination thereof.

The Adheat module 210 may determine the content of the ad using acontent modeling method that derives the content of the ad based uponwords and/or symbols used in and/or associated with the ad. In someinstances, the content of the ad may be derived from the text of the ad.In instances where text or video is supplied with the ad, opticalcharacter recognition may be used to produce text for the ad. In someinstances, the content of the ad may be derived from meta informationassociated with the ad.

The Adheat module 210 may submit the request from the advertiser 206 tothe web server 214. In response, the web server 214 may provide theAdheat module 210 with a ranked list of anonymized users that match oneor more of the characteristics specified by the advertiser 206.

An opportunity to display an ad to users ranked at the top of the listmay be more valuable to the advertiser 206 than to users ranked at thebottom of the list. A user ranked at the top of the list may be moreinfluential on a social network and may more closely fit thecharacteristics specified by the advertiser 206. The ranked list ofusers may include information for each user such as an anonymized useridentifier (prevents an advertiser from identifying the particular useron the social network), an influence score, and a relevance score. Theusers may be ranked on the list according to the influence score, therelevance score, or a combination thereof. Generally, the greater auser's influence and relevance scores, the more likely the user may bepresented at the top of the ranked list.

The influence score can be a metric of a user's influence with otherusers of a social network. The influence score may be based on a user'sactivity level and/or acquaintance relationships. A user's activitylevel can be a measure of a user's interactions on a social network.

An acquaintance relationship can be a connection between two users on asocial network, such as a friendship. A user's influence score may beaffected by a quantity and/or a significance of the user's acquaintancerelationships.

For example, a user's activity level can be determined by the qualityand/or quantity of the user's interactions with other users on a socialnetwork; the quality and/or quantity of content generated by the user onthe social network; and/or the frequency of user interaction and/orcontent generation on the social network within a period of time. A userwith a greater quality and/or quantity of interactions and/or contentgenerated may be determined to have a greater activity level than a userwith a lesser quality and/or quantity of interactions and/or contentgenerated. Additionally, a user with a greater frequency of interactionsand/or content generated within a period of time may be determined tohave a greater activity level.

User interactions on a social network may at least include posting acomment on another user's page, sending a message to another user,participating in a forum on the social network, adding another user as afriend, posting a comment in a chat room on the social network, and/orviewing another user's profile page. Content generated by a user may atleast include uploading an image or video, updating a user profile page,posting an entry to a blog, and/or updating user status information.

The quality of interactions for a user on a social network may bedetermined by evaluating the substantiveness of the interactions and/orthe responsiveness of the interaction to the context within which itappears. For example, the following two comments regarding sports may beposted: 1) “I like sports” and 2) “I love to watch sports, especiallyfootball and hockey—check out the pictures I've posted in my profilefrom my Super Bowl party.” The latter may be determined to have greaterquality because it is more substantive.

Furthering the previous example, were either of the two comments toappear in response to a discussion regarding genres of music, they wouldlikely not have a high level of quality because they are not responsiveto the context (e.g., genres of music) within which they appear. Acomment that is not highly substantive but which is responsive to thecontext within which it appears may be determined to have greaterquality than a comment that is substantive but off-topic. For example, acomment posted in the discussion regarding music genres stating “TheBlues are my favorite type of music,” may be determined to have greaterquality than the second, more substantive comment above.

Like the quality of user interactions, the quality of user generatedcontent may be evaluated for substantiveness and responsiveness tocontext as well. In addition, the quality of user generated content maybe evaluated based on originality. User generated content that isoriginal (e.g., not previously posted on the social network by anotheruser) may be determined to have a greater level of quality than contentthat is not original (e.g., copied from another user's profile page).

The quantity of a user's interactions and user generated content on asocial network may be determined by a number of interactions and anamount of content posted on the social network. For example, a userposting five comments may be determined to have a greater quantity ofactivity than a user posting two comments.

In some instances, a user's activity level may be determined by acombination of the quality and quantity of user interactions and usergenerated content. The activity level may be determined by a weightedquantity of a user's interactions and/or a weighted quantity of contentgenerated by the user, wherein each interaction and/or user generatedcontent is weighted according to its quality. For example, a userposting two comments similar to comment 2 (above) may have a greateractivity level than a user posting five comments similar to comment 1(above).

Additionally, a user's activity level may be based, at least in part, ona frequency of interactions and/or content generated by the user withina period of time. For example, a user that interacted with five otherusers and posted ten new pictures (e.g., content generation) in the lastmonth may be determined to have a greater activity level than anotheruser that interacted with only two other users and posted only five newpictures in the past month. Interactions and/or content generated mayadditionally be weighted according to a determined quality.

A user's influence score may be affected by a quantity of the user'sacquaintance relationships. A user with more friends may be moreinfluential than a user with fewer friends. As such, a user with agreater number of acquaintance relationships may produce a greaterinfluence score than a user with a lesser number of acquaintancerelationships.

A user's influence score may be affected by a significance of the user'sacquaintance relationships. A user with more significant acquaintancerelationships can have greater influence on a social network than a userwith less significant acquaintance relationships. The significance of auser's acquaintance relationship can be based on an influence score ofthe user's friend (a user connected to the user by the acquaintancerelationship) and/or whether the acquaintance relationship connectsseparate sub-graphs of a social network.

In some instances, a user's acquaintance relationship with a user havinga greater influence score may be more significant than an acquaintancerelationship with a user having a smaller influence score. In otherinstances, a user's acquaintance relationship with a user having asmaller influence score may be more significant than an acquaintancerelationship with a user having a greater influence score.

A social network of users can be represented as a graph of users (nodes)connected to each other by acquaintance relationships (edges), asexemplified by a friendship graph 218. Acquaintance relationships can beexplicit relationships among users of a social network. For instance, amutually agreed-upon friend designation among two users can be explicit.Acquaintance relationships can also be implicit. For example, eventhough users U3 and U4 do not have an explicit friendship relationship,an acquaintance relationship may implicitly exist between them if userU3 visits user U4 profile page, user U3 interacts with user U4 via aninterface on the social network (e.g., a chat room, email exchange,etc.), and/or user U3 and user U4 share a friend in common (e.g., theyboth have an explicit friendship relationship with user U5).

Within a social network graph, a sub-graph can be a group of users thathave many acquaintance relationships with each other but fewacquaintance relationships with users outside of the group. Anacquaintance relationship connecting users of two separate sub-graphsmay be more significant than an acquaintance relationship connectingusers within the same sub-graph. For example, users U2, U4, U6, and U17in social network 118 are connected via acquaintance relationshipswithin the same sub-graph. A connection between user U4 and user U10,which is part of a sub-graph separate from U4's sub-graph, can be deemedto connect users of separate sub-graphs.

The relevance score may be a metric of the similarity between a user'scharacteristics and the user characteristics an advertiser 206 hasrequested to target with an ad. As previously described in regard to anadvertiser 206 request, characteristics of a user may includedemographic information such as an age or age range, a gender,interests, an occupation, income, education, or geographic location of auser. A user with characteristics similar to the characteristicsrequested by an advertiser 206 may have a greater relevance score than auser with less similar characteristics. For example, assume users U3 is“male, age 25, likes hockey” and user U5 is “male, age 37, likes bluesmusic.” For an advertiser request to display an ad to “male” users“between the ages of 18 and 35” that like “sports,” user U3 will have agreater relevance score for the request than user U5.

In some instances, the user activity level score may be determined inview of the relevance of each interaction to an advertiser's 206request. In such an instance, each interaction may be weighted accordingto its relevance to the characteristics requested by an advertiser 206.For example, using the scenario from the previous paragraph, if users U3and U5 post the same number of substantive comments on a social networkbut more of user U5's posts relate to sports, user U5 will have agreater weighted activity level score than user U3.

In some embodiments, the web server 214 may receive the ranked list ofusers by querying a database 216 hosted on the server side 204. Thedatabase 216 may include anonymized information related to users of asocial network. For example, the anonymized information may includeinformation related to a user's characteristics, interactions on asocial network, influence on a social network, and/or relevance to anadvertiser 206 request.

In some instances, the database 216 may be populated with models relatedto users of a social network. The models may provide a synopsis of usercharacteristics, including interests, in a format that is maintained andqueried. The models may generate information for insertion into thedatabase 216 by the web server 214, or another server side 204 componentnot shown. For example, latent topic modeling may be used to generatethe models. Latent topic modeling can produce models by processing datafrom a social network (e.g., user profile page, user interactions) toderive a user characteristics (e.g., interests).

Upon receiving a ranked list of users from a web server 214, the Adheatmodule 210 may provide the ranked list of users to the advertiser 206.In turn, the advertiser 206 may provide the Adheat module 210 with a bidfor an opportunity to display an ad to one or more users included in theranked list of users. The bid may specify the minimum bid per user, themaximum bid per user, and/or the total budget for propagating the adacross a social network. The advertiser 206 may bid upon individualranked users and/or blocks of users in the ranked list.

An opportunity to display an ad to users ranked higher on the rankedlist may be more expensive than an opportunity to display an ad to alower ranked user. This may occur if the user ranked at the top of thelist is highly influential on a social network and relevant to thecharacteristics submitted by the advertiser 206 with regard to the ad.An advertiser 206 desiring to win the opportunity to display an ad to auser ranked at the top of the list will likely have to place a higherbid for that user than for lower ranked users because other advertisersare likely to bid on the same influential user.

In some implementations, the Adheat module 210 may perform some or allof the functions that are performed by the web server 214 regardingranking users of a social network. For example, in response to receivingan advertising request from the advertiser 206, the Adheat module 210may send a request for a list of users to the web server 214 withoutsending information regarding content of the advertiser's 206 ad. Inresponse, the web server 214 may provide the Adheat module 210 with alist of users and their associated information (e.g., user influencescore, user interests). The Adheat module 210 may then compute a rankingfor the users based on the received users' influence scores and/or asimilarity between the received users' interests and the content of thead. After computing a ranked list, the Adheat module 210 can display theranked list to the advertiser 206 and receive user bids from theadvertiser 206.

In such implementations, the Adheat module 210 may request from the webserver 214 users falling within a certain influence score range orinfluence score percentile. For example, the Adheat module 210 mayrequest that the web server 214 return users having an influence scoregreater than 450. In another example, the Adheat module 210 may requestthat the web server 214 return users having influence scores within thetop 10% of influence scores. The Adheat module 210 may then rank theseusers, as previously described.

The Adheat module 210 may submit the bid from the advertiser 206 to theweb server 214. The web server 214 may receive bids for the opportunityto display ads to users of a social network from a plurality ofadvertisers 206 through a plurality of Adheat modules 210 (see e.g., 104a-c in FIG. 1). The web server 214 may run an auction for theopportunity to display ads to users of a social network based upon thebids received from the advertisers 206. The auction may award theopportunity to display an ad to a user of a social network to theadvertiser with the highest bid.

For example, advertiser A1 may have submitted a maximum bid of $1.50 forthe opportunity to display an ad related to sports to anonymous user U1.Advertiser A2 may have submitted a maximum bid of $1.00 for the sameopportunity to display an ad to user U1, but advertiser A2's ad may berelated to music. The auction run by the web server 214 would award theopportunity to display an ad to user U1 to advertiser A1 because itsmaximum bid is greater.

The web server 214 may propagate an ad to a gadget 212 associated with auser 208 after an auction has awarded the opportunity to display an adto the user. In some instances, the gadget 212 is an interface thatdisplays ads on a page viewed by the users on the social network. The adof the advertiser 206 that won the auction may be transmitted to thegadget 212 (the gadget 212 may display an ad to the user 208 through acomputer display). The gadget 212 may provide the user with an interfaceallowing the user to interact with the ad. The gadget 212 may be asimple HTML or JavaScript application that can be embedded in a webpageor other application. In some instances, user interaction with an ad mayinclude the user selecting whether to propagate the ad to other usersconnected to the user by acquaintance relationships.

In some instances, a user that interacts with an ad may share in profitsof the advertisement. In some implementations, the profit shared with auser may be a percentage of the profits attributable to the user'sinteraction, a fixed amount, an amount based upon a number users thatview and/or interact with the ad attributable to the user's interaction,and/or an amount based upon characteristics and/or influence of theusers that view and/or interact with the ad attributable to the user'sinteraction. For example, a user that interacts with an ad by decidingto propagate the ad to other users of a social network may receive ashare of profits for the ad based upon the number of users to which thead is propagated.

In some implementations, propagation of an ad is attributable to a useronly if the user directly propagates the ad via one of its acquaintancerelationships. In other implementations, propagation of an ad isattributable to a user if it is possible to trace back to the user'sinteraction in a chain of propagations of the ad from user to user. Insuch an implementation, profits attributable to the propagating user maydecrease as the user's propagation becomes more distant. For example,user U1 may receive 10% of the profits for propagating an ad to user U2.However, when user U2 propagates the ad to user U3, user U1 may receiveonly 5% of the profits. Similarly, when user U3 propagates the ad touser U4, user U1 may receive only 2.5% of the profits.

The gadget 212 may propagate the ad to other users of the social networkbased upon a heat diffusion model. Heat diffusion is a concept fromthermodynamic physics. In general terms, it provides that heat spreads(diffuses) from one adjacent particle to another when there is adifference in heat between the two particles. For example, if particlesA and B are adjacent and they have temperatures of 70 and 50 degrees,respectively, heat will travel from particle A to particle B. However,heat will not travel from particle B to particle A. If both particles Aand B have temperatures of 70 degrees, no heat transfer will occur.

Using the heat diffusion model ads are propagated across a socialnetwork by assigning each user a “temperature.” An ad is transmittedfrom a propagating user to a receiving user as long as the propagatinguser has a higher “temperature” than the receiving user. In someimplementations, the heat diffusion model represents a user'stemperature using a heat index score. A user's heat index score can bebased upon a user's influence score (described above) on a socialnetwork. A user's heat index score and influence score may have a directrelationship (e.g., a more influential user will have a greater heatindex score).

Under a heat diffusion model framework, an ad can propagate between“adjacent” users. Two users may be considered to be adjacent if they areconnected to each other on a social network, as represented by theconnections between nodes on the friendship graph 218. A connectionbetween users may take the form of an acquaintance relationship. Anacquaintance relationship can be, among other things, a relationshipsignifying the users are friends, colleagues, classmates, and/or membersof the same group. In other implementations, an acquaintancerelationship can indicate that the users have viewed each othersprofiles, posted content to a profile pate for a user, and/or receivedan electronic communication (e.g., a chat request from another user).

In some implementations, an ad propagates from a propagating user to allusers connected to the propagating user with a lower heat index scorethan the propagating user. For example, user U3 is a propagating userwith a heat index score of 70. User U3 is connected to users U5, U8, andU9, which have heat index scores of 50, 35, and 80, respectively. An addisplayed to propagating user U3 will spread to users U5 and U8 becausethey have lower heat index scores. The ad will not propagate to user U9because user U9 has a greater heat index score than propagating user U3.However, when an ad is displayed to user U9 and it is serving the roleas propagating user, the displayed to user U9 ad will propagate to userU3 because user U3 has a lower heat index score.

Under the heat diffusion model, an ad propagates across users a socialnetwork using recursion. An ad is spread from a propagating user torecipient users, wherein each recipient user is connected to thepropagating user and has a lower heat index score than the propagatinguser. After being displayed the ad, each recipient user may act as apropagating user. As such, the ad is spread from a recipient user toother users connected to the recipient user having a heat index scorelower than the recipient user.

For example, using the above scenario, assume user U9 starts as apropagating user. The ad is displayed to user U9 and then propagated toits connected users having a lower heat index score. In this case, thead is propagated to user U3 because user U3 has a lower heat index scorethan user U9. User U3 then serves as a propagating user. With user U3 asthe propagating user, the ad is then propagated to users U5 and U8because users U5 and U8 have lower heat index scores than user U3. UsersU5 and U8 will then serve as propagating users. The ad will bepropagated to users connected to user U5 having a lower heat index scorethan user U5. The ad will also be propagated to users connected to userU8 having a lower heat index score than user U8.

The recursive propagation of an ad can continue until an end conditionis met. In some instances, the end condition may be the end of a budgetfor the ad having been exhausted. In other instances, the end conditionmay be the propagating user electing to not interact with the ad. Insuch an instance, the gadget 212 may replace the ad with a substitute adfor display to the user 208. In other instances, the end condition maybe the heat index score of the recipient user being greater than theheat index score of the propagating user. In other instances, the endcondition may be the recipient user already having received the ad.

The gadget 212 may transmit data regarding user 208 interaction with thead to the web server 214. The transmitted data may include informationrelated to advertisement views and clicks.

The webserver 214 may be comprised of one or more servers. The webserver214 may include an interface 220, a request scoring module 222, an adassignment module 224, and a recursive propagation module 226. Theinterface 220 may be capable of communicating with the client side 202.The request scoring module 222 may score a bid received from theadvertiser 206 for an opportunity to display an ad to at least one userof a social network. The ad assignment module 224 may assign anopportunity to display an ad to a user of a social network based uponbids scored by the request scoring module 222. The recursive propagationmodule 226 may recursively propagate an ad to users of a social networkbased upon user influence scores.

FIG. 3 is a flow chart of example process 300 for awarding anopportunity to display an ad to users of a social network based uponadvertiser requests. The processes 300 may be performed, for example, bya system such as the systems 100 and 200 and, for clarity ofpresentation, the description that follows uses the systems 100 and 200as the basis of an example for describing the processes. However,another system, or combination of systems, may be used to perform theprocess 300.

Process 300 may start at step 302 by receiving an advertiser's requestto target an ad to users of a social network with specifiedcharacteristics. The advertiser's request may be received on a serverside from a client side. For example, web server 214 may receive arequest from advertiser 206 on client side 202.

At step 304, process 300 may rank users of a social network based onsimilarity of user characteristics to the specified characteristics anda user influence score. Ranking users may be performed in response to arequest received from an advertiser. For example, the web server 214 maysort users based on profiled information and information submitted bythe advertiser 206 that specifies characteristics of users theadvertiser wishes to target. In some implementations, the web server 214may presort, or rank, users based on influence. For example, the users'influence ranking may be updated on a period basis (e.g., hourly). Thenwhen users are ranked according to advertiser submitted characteristics,the pre-calculated ranks for influence can be combined with thecharacteristic rankings to produce a user ranking based upon userinfluence and characteristics.

In some embodiments, process 300 may also include sending the rankedlist of users to the advertiser that provided the request. Someembodiments may also include receiving an advertiser bid for anopportunity to display an ad to users on the ranked list. An advertiserbid may include a bid for an opportunity to display an ad to anindividual user and/or a bid for an opportunity to display an ad to agroup of users. For example, an advertiser may bid $1.00 for anopportunity to display an ad to user U3 and $2.50 for an opportunity todisplay an ad to users U4-U8.

In some implementations, the group of users may be a range of the rankedusers. For example, an advertiser may bid on an opportunity to displayan ad to users that are ranked from 1-10 on the ranked list. In someimplementations, an amount bid on a group of users may correspond to anamount for all of the users within the group (e.g., $1.00 for all usersU4-U8). In other implementations, an amount bid on a group of users maycorrespond to an amount for each user within the group (e.g., $1.00 foreach user U4-U8).

Process 300 can score advertiser bids for an opportunity to display anad to users of a social network at step 306. For example, scoring can bebased upon an amount bid by an advertiser for an opportunity to displayan ad to a user of a social network. There may be a direct relationshipbetween a resulting score and an amount bid (e.g., the greater the bid,the greater the resulting score).

The bids may also be scored based on how relevant users have found theadvertisers' ads in the past. For example, a database at the server side204 may store information indicating a historical click-through rate forads submitted by particular advertisers. Bids from advertisers havingads with higher click-through rates may be scored higher than bids fromadvertisers that have ads with lower click-through rates.

In some implementations, an advertiser bid for an opportunity to displayan ad to a group of users may be provided one score. In someimplementations, an advertiser bid for an opportunity to display an adto a group of users may be provided a score for each individual user ofthe group. In some embodiments, a score for an individual user of thegroup may be equal scores for the other users of the group (e.g., scorefor individual user=score for group of users/number of users). In otherembodiments, a score for an individual user of the group may be a shareof a score for the group proportionate to the user's influence score inrelation to the influence scores for the other users (e.g., score forindividual user=score for group of users×(influence score for individualuser/aggregate influence score for group)).

At step 308, an advertising opportunity can be assigned to anadvertiser. Assigning the advertising opportunity may be based on thescore of advertiser bids and/or the score associated with the users towhich the ad will be displayed. An advertiser may be assigned anadvertising opportunity for an individual user and/or for a group ofusers. Bids considered when assigning an advertising opportunity may belimited to bids received within a specified timeframe and/or bids fordisplaying an ad to a user within a specific date range.

In some implementations where an advertiser submits a group bid and thegroup bid is scored for each user within the group, an opportunity todisplay an ad to the group may be assigned to the advertiser if, foreach user within the group, a corresponding bid score is greater thanbid scores from other advertisers. For example, if an advertiser bids todisplay an ad to users U4-U8 and the bid is scored for each userindividually (e.g., 1.0 score for each user), an opportunity to displayan ad to the group may be awarded to the advertiser so long as no otheradvertiser has a bid score greater than (or less than, depending on thescoring technique) 1.0 for any of the users U4-U8.

In some other implementations where an advertiser submits a group bidand the group bid is scored for each user within the group, anopportunity to display an ad to each user within the group may beevaluated and assigned for each user individually. For example, if anadvertiser bids to display an ad to users U4-U8 and the bid is scoredfor each user individually (e.g., 1.0 score for each user), anopportunity to display an ad to user U4 may be assigned to theadvertiser so long as no other advertiser has a bid score of greaterthan 1.0 for user U4. The opportunities to display an ad to users U5-U8may be assigned in a similar manner, independent of the evaluation andassignment of opportunities to display ads to other users within thegroup.

In some implementations where an advertiser submits a group bid and thegroup bid is provided a group score, an opportunity to display to thegroup may be assigned to the advertiser with the greatest scored bid forthe group. For example, if a first and a second advertiser have bidscores of 2.5 and 2.7 for an opportunity to display an ad to usersU4-U8, the second advertiser may be assigned the opportunity to displaythe ad to users U4-U8.

In some implementations where an advertiser submits a group bid and thegroup bid is provided a group score, the opportunity may be assigned bydetermining the minimum score required to display the ad to eachindividual user, aggregating the minimum scores for the group, andassigning the opportunity to the advertiser if the aggregated minimumscore is less than or equal to the group bid score. For example, if anadvertiser's bid score for a group of users U4-U8 is 2.5 and anaggregate minimum score for displaying the ad to the group is 2.4 (e.g.,a minimum score for displaying an ad to each of the users U4-U8 may be1.0, 0.8, 0.2, 0.2, and 0.2, respectively), the advertiser may beassigned the opportunity to display to the group. A minimum score torequired to display an ad to a user may be determined by ascertainingthe greatest bid score for the user and incrementing the greatest bidscore by a predetermined amount and/or percentage.

In some implementations, there may exist more than one opportunity todisplay an ad to a user within a time period. These opportunities may beassigned to the same or different advertisers depending on the bidscores. For example, if there are three opportunities to display an adto a user within a time period, bids with the three greatest scores maybe assigned the three opportunities. For instance, if four advertisers(A1-A4) bid on opportunities to display ads to four users (U1-U5) andthere are three opportunities available per user, advertisers with firstthrough third place bids for a user will be awarded an opportunity todisplay an ad to the user. If A1 bids $2.00 for users U1-U4, A2 bids$1.50 for users U1-U3, A3 bids $1.00 for users U2-U4, and A4 bids $0.50for users U1-U4, then advertising opportunities may be assigned for eachuser as follows: U1-A1, A2, A4; U2-A1, A2, A3; U3-A1, A2, A3; U4-A1, A3,A4; U5—no opportunities assigned.

In some implementations, when multiple opportunities to display an ad toa user exist, a single advertiser may be assigned more than one of themultiple opportunities if the single advertiser provided a bid for morethan one of the multiple opportunities.

After assigning an advertising opportunity for a user or users to anadvertiser, the advertiser's ad can be output to the user or users atblock 310. The user or users receiving the ad can be on a client side,such as the users specified in social network 118 or user 208.

In some implementations, users of a social network for which anadvertising opportunity was not assigned, such as user U5 in thepreceding example, may receive default ads in place of ads assigned toan advertiser (e.g., default ads may include ads for the social network,profiles of other users on the social network, ads fornon-profit/charitable organizations, etc.).

FIG. 4 is a flow chart of example process 400, respectively, forrecursively propagating an ad across users of a social network. Theprocesses 400 may be performed, for example, by a system such as thesystems 100 and 200 and, for clarity of presentation, the descriptionthat follows uses the systems 100 and 200 as the basis of an example fordescribing the processes. However, another system, or combination ofsystems, may be used to perform the process 400.

Process 400 may begin at steps 402 and/or 404. At step 402, process 400can determine acquaintance relationships (e.g., friendship) among usersof a social network. At step 404, process 400 can determine activitylevels (e.g., number of posts, friend adds, etc.) for the users of asocial network.

At step 406, process 400 may generate an influence score for the usersof a social network using the determined user acquaintance relationshipsand the determined user activity levels. Combining a user's acquaintancerelationships and activity level to generate an influence score may beperformed differently depending on configurations of the social networkand/or advertiser preferences. For example, a first social network maybe configured to weight acquaintance relationships twice as heavily asactivity level while a second social network may be configured to weightacquaintance relationships and activity level equally.

In some implementations, a social network may have multipleconfigurations that are used to generate an influence score for users ofthe social network. The social network determination of which one of themultiple configurations to use may depend on conditions within thesocial network and/or a type of ad to be displayed. For example, aconfiguration used by the social network during a weekday may bedifferent from a configuration used during a weekend. Differentconfigurations may be determined by a social network based upondemographic information of users accessing the social network duringvarious time periods.

In some implementations, a social network may defer to an advertiser'sweighting of acquaintance relationships and activity level whengenerating influence scores for users of a social network. Use ofinfluence scores generated by deferring to an advertiser's weighting maybe limited to ads from the advertiser. An advertiser may provide asocial network with weightings that apply to specific ads from theadvertiser.

Generation of influence scores for users of a social network at step 406may be performed at regular intervals and/or at the occurrence ofcertain events. For example, influence scores may be generated every tenminutes, half-hour, hour, six hours, twelve hours, day, 3 days, week,and/or month. As another example, influence scores may be generated whena certain number of activity events within the social network haveoccurred (e.g., generate influence score every time: 1000 comments areposted on the social network, 10 users join the social network, 100acquaintance relationships are formed, etc.).

In some implementations, generation of an influence scores for users ofa social network at step 406 may be triggered by the display of an ad toa user of a social network. For example, every time an ad is to bedisplayed on a social network to a user for the first time, the socialnetwork may generate influence scores for users of the social network.When generation is triggered by an ad, the generation of influencescores may be limited to users within a sub-graph of a user to beinitially targeted with the ad.

In some implementations, process 400 may display an ad to a user of asocial network. An opportunity to display the ad to the user may havebeen awarded to an advertiser that won the opportunity through a biddingprocess, as outline, for example, with reference to FIG. 3.

At step 408, process 400 may determine whether an influence score for apropagating user is greater than an influence score for a recipientuser. The propagating user may be a user to whom an ad is displayed. Therecipient user may be a user connected to the propagating user via anacquaintance relationship (e.g., friendship). If the influence score forthe propagating user is greater than the influence score for a recipientuser, process 400 may propagate the ad from the propagating user to therecipient user at step 410.

In some instances, steps 402-406 regarding generation of influencescores may not be performed until step 408. In such an instance, steps402-406 may only be performed for the propagating user and the recipientuser. For example, after an ad is displayed to a propagating userprocess 400 may determine the influence scores for the propagating andrecipient users.

At step 410, propagating an ad from a propagating user to a recipientuser may involve displaying an ad to the recipient user. The addisplayed to the recipient user may be the same ad displayed to thepropagating user. After propagating the ad to the recipient user at step410, process 400 may return to step 408. However, when returning to step408, the recipient user may serve as a propagating user and a userconnected to the recipient user via an acquaintance relationship mayserve as a recipient user.

For example, if user U1 is initially a propagating user and user U2 isinitially a recipient user and U1's influence score is greater thanU2's, then an ad displayed to U1 may propagate to U2. After the ad ispropagated to U2, process 400 may return to step 408 with U2 serving asa propagating user and user U3, connected to U2 via an acquaintancerelationship, serving as a recipient user.

An ad may recursively propagate among users of a social network at steps408 and 410. Steps 408 and 410 may be performed for each acquaintancerelationship of a propagating user. For example, an ad displayed to thepropagating user may be propagated to each the propagating user'sacquaintance relationships with an influence score less than thepropagating user's. Subsequently, each user receiving the ad from thepropagating user may propagate the ad to each of its acquaintancerelationships having a lesser influence score.

Recursive propagation of an ad at steps 408 and 410 may continue untilprocess 400 determine an influence score for a propagating user is notgreater than an influence score for a recipient user. When such adetermination is made, process 400 may end. Recursive propagation mayalso end when a condition is met that does not permit the continuedpropagation of the ad (e.g., conditions outlined with regard to FIG. 7).

In some instances, propagation using a heat diffusion model can belimited based on a degree of separation between the users. For example,if the ad has propagated to a user greater than 6 degrees of separationfrom the originating user, the propagation may stop regardless of theheat index score of adjacent users.

FIG. 5 is a flow chart of example process 500, respectively, forgenerating a model of a user's interests from user generated content.The processes 500 may be performed, for example, by a system such as thesystems 100 and 200 and, for clarity of presentation, the descriptionthat follows uses the systems 100 and 200 as the basis of an example fordescribing the processes. However, another system, or combination ofsystems, may be used to perform the process 500.

Process 500 may begin at step 502 by collecting information about a userbased on user generated content. The information collected may bedemographic information (e.g., age, gender, geographic location, etc.)and/or may pertain to a user's interests (e.g., sports, music, etc.).User generated content can include any content generated by a user of asocial network, such as information a user provides on his/her ownprofile page (e.g., interests, age, gender, etc.), groups a user joins(e.g., a hiking club group), and/or comments a user posts (e.g., statusupdates, comments posted on another user's profile page).

In some instances, visual and audio media (e.g., music, photos, videos)posted by a user may also be collected. Meta-tags associated with thevisual and audio content may be collected. In some instances, anaudio/video content analyzer may be used to derive information regardingthe visual and audio content. For example, an audio/visual analyzer mayidentify an audio file by comparing a calculated file signature for theaudio file against a database of known audio files. In another example,an audio/visual analyzer may attempt to tease-out information regardingthe content of a photo by searching for items and/or logos in the photothat may be associated with a particular topic (e.g., finding baseballhats, baseball gloves, and/or baseball team logos in an image mayindicate the photo relates to baseball.

At step 504, process 500 can input the collected information into amachine learning algorithm. The machine learning algorithm may be alatent topic modeling algorithm. A latent topic modeling algorithm mayexamine the collected information and, based upon the topics that arepresented, generate a list of topics that are pertinent to a user. Insome implementations, the algorithm may check the collected informationagainst a database of keywords that are associated with topics. Thesekeywords and associated topics may be dynamically learned and adjustedby the algorithm.

At step 506, process 500 may generate a topic model that provides auser's interests based upon the collected information. A topic model fora user may provide a list of attributes associated with a user'sinterests. A topic model may provide an indication of how interested auser is in a particular topic (e.g., a user is most interested in sportsand then music). After a topic model is generated, process 500 may end.

In generating a topic model, previous topic models may also be examinedin order to determine changes in a user's interests over time. Forinstance, a topic model may provide that a user has recently becomeinterested in genealogy and that the user's interest in sports has beendeclining over the past year.

For example, a user U10 may have a profile page with blog entriesregarding soccer and skiing and photos from a recent professional soccermatch the user attended. The user U10 may also be a member of a videogame group on the social network and may post comments on profile pagesof other users regarding soccer, movies, and snow conditions at skiareas. All of this information would be collected by process 500 andinput into a machine learning algorithm. Using the machine learningalgorithm, process 500 may then generate a topic model for user U10. Thetopic model may list the following interests in order from a greatestamount of interest to a least amount of interest: soccer, skiing,movies, and video games. By examining previous topic models for userU10, the topic model may also provide that soccer has consistently beenthe user U10's greatest interest, that skiing is a cyclical interestthat peaks in winter, and that movies and video games has decreased overthe past year.

FIG. 6 is a flow chart of example process 600, respectively, for anadvertiser to place bids for opportunities to display ads to users of asocial network. The processes 600 may be performed, for example, by asystem such as the systems 100 and 200 and, for clarity of presentation,the description that follows uses the systems 100 and 200 as the basisof an example for describing the processes. However, another system, orcombination of systems, may be used to perform the process 600.

Process 600 may begin at step 602 by an advertiser inputting parametersthat describe the characteristics of users the advertiser desires totarget with an ad. Characteristics can include demographic information(e.g., age, gender, geographic location) and/or interests (e.g., sports,music). The advertiser may input this information through an interfaceon a client side, such as the Adheat interface 210 of system 200, whichmay in-turn be submitted to a server side, such as the web server 214 ofsystem 200.

At step 604, process 600 receives a list of ranked users from a server,where the rank is based on a similarity of the characteristics and userinfluence score. The ranked list of users may be generated on a server,such as web server 214, in a manner similar to that described above withregard to FIGS. 1-3. The ranked list of users may be received though aninterface, such as the Adheat interface 210 of system 200.

For example, an advertiser A1 may input parameters for users to betargeted with its ad such as males, between the ages of 18 and 35, whoare interested in sports. The advertiser A1 may then receive a list ofranked users U1-U5. The user U1, ranked at the top of the list, may mostclosely match the characteristics submitted by the advertiser A1 and mayalso have a high influence score on a social network. The user U5,ranked at the bottom of the list, may least match the characteristicssubmitted by the advertiser A1 and/or may have a low influence score onthe social network.

At step 606, the advertiser may input a maximum and minimum cost theadvertiser is willing to pay for displaying ads per user. In someinstances, the advertiser may input a maximum and a minimum cost theadvertiser is willing to pay for displaying ads to a block or group ofusers. The maximum and minimum cost may be input though an interface,such as the Adheat interface 210 of system 200.

Using the previous example, a maximum and minimum cost for users U1-U5that the advertiser A1 may be willing to pay may be directly correlatedto the rank of each user on the list received at step 604. Theadvertiser A1 may input a maximum and minim cost for user U1 as $1.00and $0.50, respectively. However, the advertiser A1 may input a maximumand minim cost of only $0.25 and $0.05, respectively, for user U5. Insome instances, the advertiser A1 may not input a bid for lower rankedusers, such as user U5.

At step 608, the advertiser inputs an overall budget for displaying anad. An overall budget may be the maximum amount the advertiser iswilling to spend for the ad to be displayed to the bid upon users and tobe propagated to other users of a social network. Once the budget isexhausted, the ad may stop being displayed to users of a social network.The overall budget may be input though an interface, such as the Adheatinterface 210 of system 200.

In some instances, the budget may be for a periodic or specified timeperiod. For example, an advertiser may provide that a daily budget fordisplaying the ad is $50.00. Once the daily budget is exhausted, the admay not be displayed to users of the social network until the next dailyperiod begins.

At step 610, the advertiser may submit its bids (e.g., maximum andminimum costs) for opportunities to display an ad to users from theranked list. Along with the bids, the advertiser may submit the overallbudget for the ad as well. The bids may be submitted by the advertiserthrough an interface, such as the Adheat interface 210 of system 200,and received by a component on a server side, such as the web server214. After the advertiser submits its bid, the process 600 may end.

Steps 606-610 may collectively represent a bidding process 612 performedby an advertiser for opportunities to display an ad to users of a socialnetwork. The bidding process 612 may be performed periodically by anadvertiser for a particular ad (e.g., monthly). In some instances, thebidding process 612 may be automated for an advertiser based upon theadvertiser's previous bids for similar ads. For example, if anadvertiser has provided average maximum and minimum bids for a first andfifth ranked user of $1.00-$0.50 and $0.25-$0.05, respectively, thebidding process 612 may automatically use these average values for afirst and fifth ranked user as part of a new bid.

In some instances, the automatic bid amount may be based, at least inpart, on a user's influence score and rank in the list of ranked users.For example, an automatic bid amount may be based upon an amount bid peruser influence score over user rank (e.g., amount bid/(user influencescore/user rank)). Since the user influence score and the user rank maybe provided to an advertiser at step 604, an amount bid may beautomatically calculated for each user on the ranked list. In someinstances, a threshold value for a calculated amount bid (e.g., amountbid greater than $0.01), a user influence score (e.g., score greaterthan average influence score), and/or a user rank (e.g., rank within thetop 25) may need to be met in order for an automatic bid to be placedfor a user.

FIG. 7 is a flow chart of example process 700, respectively, forpropagating an ad from a propagating user to a recipient user. Theprocesses 700 may be performed, for example, by a system such as thesystems 100 and 200 and, for clarity of presentation, the descriptionthat follows uses the systems 100 and 200 as the basis of an example fordescribing the processes. However, another system, or combination ofsystems, may be used to perform the process 700.

Process 700 may begin at step 702 by a user of a social network logginginto the social network. At step 704, the user may view an ad in agadget. A gadget may be an interactive interface embedded within theuser's view of the social network, such as the gadget 212 described withreference to system 200. For example, the gadget may be an interactivewidget that is displayed in the user's web page based view of the socialnetwork. The gadget may display an ad which an advertiser won anopportunity to display to the user. The gadget may also display adspropagated to the user from another user on the social network.

At step 706, the process 700 may determine whether the user hasinteracted with the ad being displayed in the gadget. User interactionmay include clicking on the ad, providing an indication of attention tothe ad (e.g., pressing a “play” button for a video ad), and/or decidingto propagate the ad to other users of the social network. If the userinteracts with the ad displayed in the gadget, then process 700 proceedsto step 708. If the user does not interact with the ad displayed in thegadget, then process 700 does not propagate the ad at step 718.

In some implementations, at step 706, the process 700 may furtherdetermine whether the user's interaction endorses propagation of the adto other users of the social network (e.g., propagation to usersconnected to the user by an acquaintance relationship). For example, forad propagation to occur, a user may have to indicate it consents topropagation through some sort of interaction with the gadget (e.g.,clicking a “Propagate ad” button). If the user indicates consent topropagation, then process 700 may proceed to step 708. Even though auser may interact with the ad, if the user does not endorse propagationof the ad, then process 700 does not propagate the ad at step 718.

At step 708, process 700 determines whether the budget for the ad hasexpired. As described with reference to process 600, an advertiser mayprovide an overall budget for displaying an ad. Once the budget has beenused-up by displaying the ad to users of a social network, the ad maynot be propagated. If the budget has not been exhausted, then process700 proceeds to step 710. If the budget has been exhausted, the process700 does not propagate the ad at step 718.

At step 710, process 700 determines whether a time period for displayingthe ad has expired. An advertiser may specify that an ad is to bedisplayed within a specific period of time. For example, regarding an adfor a music concert, the advertiser may specify that the ad should beshown up to the time of the concert, but not afterward. If the timeperiod for displaying the ad has not expired, then process 700 proceedsto step 712. If the time period for displaying the ad has expired, thenprocess 700 does not propagate the ad at step 718.

At step 714, process 700 determines whether the ad has already beenpropagated to all of the users connected to the user by an acquaintancerelationship. As described above, an acquaintance relationship can be aconnection among two users of a social network, such as a friendshiprelationship, posting a comment on another user's profile page, viewinganother user's profile page, interacting with another user in an socialnetwork facilitated activity (e.g., playing an online game togetherthrough the social network, conversing via a chat room or discussionthread), and/or belonging to similar social group or organization on thesocial network. If the ad has not been propagated to at least one of theusers connected to the user by an acquaintance relationship, thenprocess 700 proceeds to step 714. If the ad has already been propagatedto all of the users connected to the user by an acquaintancerelationship, then process 700 does not propagate the ad at step 718.

At step 714, process 700 determines whether a heat diffusion balance hasbeen reached between the user and users connected to it by anacquaintance relationship to whom the ad has not already beenpropagated. As described above with reference to step 408 of process400, an ad may propagate from one user to another as long as a heatdiffusion balance has not yet been reached. A heat diffusion balance maybe reached when an influence score for a propagating user is less thanor equal to an influence score for a recipient user. If a heat diffusionbalance has been not been reached for at least one user connected to theuser by an acquaintance relationship, then the process 700 proceeds tostep 716. If a heat diffusion balance has been reached for all usersconnected to the user by an acquaintance relationship, then process 700does not propagate the ad at step 718.

At step 716, process 700 propagates the ad from the user (e.g., thepropagating user) to a recipient user (e.g., a user connected to thepropagating user by an acquaintance relationship). Recipient users maybe users that are connected to the propagating user by an acquaintancerelationship, that have an influence score less than the influence scoreof the propagating user, and to whom the ad has not yet been propagated.In some implementations, the ad may be propagated to all recipientusers. In other implementations, the ad may be propagated to onlyrecipient users meeting a criterion set by the advertiser. For example,the advertiser may indicate that propagation to a recipient user shouldoccur only if the recipient user has an influence score that is greaterthan 80% of the influence score of the propagating user. Afterpropagating an ad to a recipient user, process 700 may end.

At step 718, process 700 does not propagate the ad from the user tousers connected to it by an acquaintance relationship. After step 718,process 700 proceeds to step 720. At step 720, process 700 determineswhether there is replacement ad available to be displayed to the user inthe gadget. A replacement ad may be another ad that can be displayed tothe user (e.g., an advertiser won an opportunity to display thereplacement ad to the user, an ad has been propagated to the user). If areplacement ad is available to be displayed to the user, then process700 may return to step 704 and may display the replacement ad to theuser in the gadget. If a replacement ad is not available, then process700 may end.

FIG. 8 is a schematic diagram of a computer system 800. The system 800can be used for the operations described in association with any of thecomputer-implement methods described previously, according to oneimplementation. The system 800 is intended to include various forms ofdigital computers, such as laptops, desktops, workstations, personaldigital assistants, servers, blade servers, mainframes, and otherappropriate computers. The system 800 can also include mobile devices,such as personal digital assistants, cellular telephones, smartphones,and other similar computing devices. Additionally the system can includeportable storage media, such as, Universal Serial Bus (USB) flashdrives. For example, the USB flash drives may store operating systemsand other applications. The USB flash drives can include input/outputcomponents, such as a wireless transmitter or USB connector that may beinserted into a USB port of another computing device.

The system 800 includes a processor 810, a memory 820, a storage device830, and an input/output device 840. Each of the components 810, 820,830, and 840 are interconnected using a system bus 850. The processor810 is capable of processing instructions for execution within thesystem 800. The processor may be designed using any of a number ofarchitectures. For example, the processor 810 may be a CISC (ComplexInstruction Set Computers) processor, a RISC (Reduced Instruction SetComputer) processor, or a MISC (Minimal Instruction Set Computer)processor.

In one implementation, the processor 810 is a single-threaded processor.In another implementation, the processor 810 is a multi-threadedprocessor. The processor 810 is capable of processing instructionsstored in the memory 820 or on the storage device 830 to displaygraphical information for a user interface on the input/output device840.

The memory 820 stores information within the system 800. In oneimplementation, the memory 820 is a computer-readable medium. In oneimplementation, the memory 820 is a volatile memory unit. In anotherimplementation, the memory 820 is a non-volatile memory unit.

The storage device 830 is capable of providing mass storage for thesystem 800. In one implementation, the storage device 830 is acomputer-readable medium. In various different implementations, thestorage device 830 may be a floppy disk device, a hard disk device, anoptical disk device, or a tape device.

The input/output device 840 provides input/output operations for thesystem 800. In one implementation, the input/output device 840 includesa keyboard and/or pointing device. In another implementation, theinput/output device 840 includes a display unit for displaying graphicaluser interfaces.

The features described can be implemented in digital electroniccircuitry, or in computer hardware, firmware, software, or incombinations of them. The apparatus can be implemented in a computerprogram product tangibly embodied in an information carrier, e.g., in amachine-readable storage device for execution by a programmableprocessor; and method steps can be performed by a programmable processorexecuting a program of instructions to perform functions of thedescribed implementations by operating on input data and generatingoutput. The described features can be implemented advantageously in oneor more computer programs that are executable on a programmable systemincluding at least one programmable processor coupled to receive dataand instructions from, and to transmit data and instructions to, a datastorage system, at least one input device, and at least one outputdevice. A computer program is a set of instructions that can be used,directly or indirectly, in a computer to perform a certain activity orbring about a certain result. A computer program can be written in anyform of programming language, including compiled or interpretedlanguages, and it can be deployed in any form, including as astand-alone program or as a module, component, subroutine, or other unitsuitable for use in a computing environment.

Suitable processors for the execution of a program of instructionsinclude, by way of example, both general and special purposemicroprocessors, and the sole processor or one of multiple processors ofany kind of computer. Generally, a processor will receive instructionsand data from a read-only memory or a random access memory or both. Theessential elements of a computer are a processor for executinginstructions and one or more memories for storing instructions and data.Generally, a computer will also include, or be operatively coupled tocommunicate with, one or more mass storage devices for storing datafiles; such devices include magnetic disks, such as internal hard disksand removable disks; magneto-optical disks; and optical disks. Storagedevices suitable for tangibly embodying computer program instructionsand data include all forms of non-volatile memory, including by way ofexample semiconductor memory devices, such as EPROM, EEPROM, and flashmemory devices; magnetic disks such as internal hard disks and removabledisks; magneto-optical disks; and CD-ROM and DVD-ROM disks. Theprocessor and the memory can be supplemented by, or incorporated in,ASICs (application-specific integrated circuits).

To provide for interaction with a user, the features can be implementedon a computer having a display device such as a CRT (cathode ray tube)or LCD (liquid crystal display) monitor for displaying information tothe user and a keyboard and a pointing device such as a mouse or atrackball by which the user can provide input to the computer.

The features can be implemented in a computer system that includes aback-end component, such as a data server, or that includes a middlewarecomponent, such as an application server or an Internet server, or thatincludes a front-end component, such as a client computer having agraphical user interface or an Internet browser, or any combination ofthem. The components of the system can be connected by any form ormedium of digital data communication such as a communication network.Examples of communication networks include a local area network (“LAN”),a wide area network (“WAN”), peer-to-peer networks (having ad-hoc orstatic members), grid computing infrastructures, and the Internet.

The computer system can include clients and servers. A client and serverare generally remote from each other and typically interact through anetwork, such as the described one. The relationship of client andserver arises by virtue of computer programs running on the respectivecomputers and having a client-server relationship to each other.

Although a few implementations have been described in detail above,other modifications are possible. Moreover, other mechanisms forproviding advertisements to users of a social network may be used. Inaddition, the logic flows depicted in the figures do not require theparticular order shown, or sequential order, to achieve desirableresults. Other steps may be provided, or steps may be eliminated, fromthe described flows, and other components may be added to, or removedfrom, the described systems. Accordingly, other implementations arewithin the scope of the following claims.

1. A computer-implemented method comprising: receiving at a server arequest from an advertiser to target an ad to users of acomputer-implemented social network, the request comprising datarepresenting characteristics of the users that the advertiser desires totarget; ranking by the server the users based on how similar the users'characteristics are to the received characteristics and an influencescore for each user that indicates how influential the user is withinthe computer-implemented social network; scoring by the server theadvertiser's request based on a bid from the advertiser for anopportunity to display the ad to one or more of the users targeted bythe advertiser; assigning by the server the opportunity to display thead to the one or more users targeted by the advertiser based on acorrelation between a score of the advertiser's request and one or morerankings of the one or more users; and outputting by the server the adfor display on one or more clients associated with the one or more usersassigned to the ad.
 2. The method of claim 1, further comprisinggenerating by the server the influence score for a user based on theuser's level of activity on the computer-implemented social network. 3.The method of claim 2, further comprising determining by the server thelevel of activity of the user based on a quality or type of contentgenerated by the user on the computer-implemented social network; aquality or type of interactions with other users on thecomputer-implemented social network; or frequency of user interactionwithin the computer-implemented social network over a period of time. 4.The method of claim 2, further comprising determining by the server thelevel of activity of the user based on an quality of content generatedby the user on the computer-implemented social network or a quality ofinteractions with other users on the computer-implemented socialnetwork.
 5. The method of claim 3, wherein the influence score for auser indicates greater influence when the content generated by the useror the interactions with other users are determined to be substantive,wherein substantive content comprises original content that is greaterthan a threshold amount of content.
 6. The method of claim 1, furthercomprising generating by the server the influence score for a user basedon the user's acquaintance relationships on the computer-implementedsocial network, wherein an acquaintance relationship comprises abi-directional relation between two users of the social network.
 7. Themethod of claim 6, wherein an acquaintance relationship comprises a linkbetween two users of the computer-implemented social network.
 8. Themethod of claim 6, wherein a user with a greater number of acquaintancerelationships has an influence score indicating greater influence than auser with a smaller number of acquaintance relationships.
 9. The methodof claim 6, wherein the user's influence score is based on influencescores of other users who have acquaintance relationships with the user.10. The method of claim 6, wherein the user's influence score is basedon a significance of a type of the user's acquaintance relationships.11. The method of claim 10, wherein the computer-implemented socialnetwork is at least partially represented using a graph comprising usernodes connected by acquaintance relationships, and wherein a first typeof acquaintance relationship that connects a sub-graph portion of thegraph to the rest of the graph has a greater significance than a secondtype of acquaintance relationship that does not connect a sub-graphportion of the graph to the rest of the graph.
 12. The method of claim1, wherein the data representing characteristics of the users relate toan age, a gender, keywords describing interests, or a geographiclocation.
 13. The method of claim 1, further comprising transmitting bythe server a list of the ranked of users to the advertiser.
 14. Themethod of claim 1, wherein the bid from the advertiser includes aminimum bid per user, a maximum bid per user, or a total budget for thead.
 15. The method of claim 1, further comprising applying by the servera weighting preference comprising a first weight indicating how muchsignificance to assign to the similarity between the user'scharacteristics and the received characteristics in the ranking of usersand a second weight indicating how much significance to assign to theinfluence score in the ranking of users.
 16. The method of claim 15,wherein ranking the users further comprises calculating a first weightedvalue by applying the first weight to the similarity to the receivedcharacteristics for each user, calculating a second weighted value byapplying the second weight to the influence score for each user, andcombining the first weighted value with the second weighted value. 17.The method of claim 15, wherein the weighting preference is a preferenceprovided by the advertiser.
 18. The method of claim 15, wherein theweighting preference is predetermined.
 19. The method of claim 15,further comprising calculating by the server a weighting preferencebased upon a content of the ad, weighting preferences for previous adswith similar content, or an effectiveness of the previous ads.
 20. Asystem for assigning an opportunity to display an ad to users of asocial network, comprising: one or more servers; an interface to one ormore of the servers to receive from an advertiser a request to target anad to users of a social network, the request comprising datarepresenting characteristics of the users that the advertiser desires totarget; means for ranking the users based on how similar the users'characteristics are to the received characteristics and an influencescore for each user that indicates how influential the user is withinthe social network; a request scoring module installed on the one ormore servers to score the advertiser's request based on a bid from theadvertiser for an opportunity to display the ad to one or more of theusers targeted by the advertiser; and an ad assignment module installedon one or more of the servers to: assign the opportunity to display thead to the one or more users targeted by the advertiser based on acorrelation between a score of the advertiser's request and one or morerankings of the one or more users, and output the ad for display on oneor more clients associated with the one or more users assigned to thead.
 21. The system of claim 20, wherein the means for ranking the usersgenerates the influence score for a user based on the user's level ofactivity on a social network.
 22. The system of claim 20, wherein themeans for ranking the users generates the influence score for a userbased on the user's acquaintance relationships on the social network.23. The system of claim 20, wherein the data representingcharacteristics of the users relate to an age, a gender, interests, or ageographic location of users on a social network.
 24. Acomputer-implemented method comprising: receiving at a serverinformation related to a content of an ad from an advertiser; creatingby the server an ordered list of users of a computer-implemented socialnetwork based on a likelihood a user will be receptive to the content ofthe ad and an amount of influence a user has over other users of thecomputer-implemented social network; receiving at the server a bid fromthe advertiser for a right to display the ad to a user provided in theordered list of users; awarding by the server the right to display thead to the user to the advertiser if the bid from the advertiser isgreater than other bids received within a time period from otheradvertisers for the right to display the ad to the user, wherein the bidfrom the advertiser is received within the time period; and outputtingby the server the ad for display on a client associated with the user.25. The method of claim 24, further comprising determining by the servera likelihood a user of the computer-implemented social network will bereceptive to the content of the ad by comparing the content of the ad toinformation related to interests of the user.
 26. The method of claim24, further comprising determining by the server an amount of influencea user has over other users of the computer-implemented social networkby assessing the user's relationships with the other users of thecomputer-implemented social network and the user's level of activity onthe social network.